I just ordered the clay bar from Griots, had to wait till my Mequiars clay bar was used up, so we'll see how it compares as soon as it comes in. As far as "Z" goes, well, alot of people on other boards rave about it, but I'm not convinced and probably never will be. Now that I've tried Griots and learned more about them, they truly have the best products out there. I know they're not available in stores, just like "Z" isn't, but for what they put into their stuff, its #1 in my book. Case in point, the carnauba paste wax they offer is 33% carnauba content which is the most on the market today. They've even stepped up and offered a polymer, like "Z", its called paint sealant and its supposed to be good for ONE year, but they suggest adding their new spray wax to "enhance" your cars protection, kinda like "Z" has with their product. www.griotsgarage.com